How do you understand that phrase?
The Theotokos helps us in three ways - she prays on our behalf to Christ Pantocrator, and her prayers are known for efficacy, and also she points us to our Son and commands us to follow Him - we see both attributes on display during the Wedding Feast at Cana, and finally as the Mother of God, it is from her that Christ put on our human nature, facilitating our redemption, and indeed, the Gospel read at Marian feasts in the Eastern Orthodox Church it might surprise you to learn concludes with Luke 11:27-28, for indeed only our Glorious Lady Theotokos and Ever Virgin Mary, who is immaculate* managed to keep His commandments, but still required His salvation due to original sin, a salvation she obtained by virtue of risking her life to bear him.
Thus when we pray for her to save us, we are asking her to pray on her behalf, in recognition of the fact that she has pointed us to Her Son, our Lord, God and Savior Jesus Christ, commanding us to follow His instructions, and consequently those of the Father and Holy Spirit, the precious and life-giving Trinity, “ever One God” to use an elegant phrase from the Anglican hymnal, as is attested once more in the Gospel according to John, and the fact that she is the means by which the Only Begotten Son and Word of God became incarnate as the Son of Man for our salvation.
The efficacy of her prayers is demonstrated at the Wedding Feast in Cana, and also makes sense, in light of the fact that Our Lady had the most intimate relationship with God of any human, since the closest relationship any human can enjoy is with his or her own mother. Thus, the Theotokos is uniquely blessed, and will be held as blessed by all generations, for she as the Mother of God was and is closer to Him physically and emotionally than anyone else. This is also why on the occasion of her repose her body was assumed into Heaven on the feast of the Dormition - Rome may only have made this a dogma in 1955, but we Orthodox have regarded it as dogmatic since at least the fourth century, and likely much longer than that, for it has always been celebrated in our liturgy (everything celebrated in the Orthodox liturgy is dogmatic, on the basis of
Lex Orandi, Lex Credendi, an approach also theoretically followed by the Anglicans, which is one of many reasons why historically there have been such good relations between the Orthodox and Anglicans, although one could argue varying degrees of churchmanship compromise this in Anglicanism by resulting in the same liturgical text having multiple interpretations depending on the churchmanship of the reader; I would argue that a prayer book is like the Bible, in that what St. Isidore of Seville said certainly applies - the meaning ultimately is in the interpretation, not the reading, since the right Scripture wrongly interpreted is still wrong, as demonstrated by the Arians for example, who managed to somehow read John ch. 1 and not interpret it as speaking of the Incarnation of Christ (a phenomenon we also encounter among some contemporary Christians, who usually are not Christologically neo-Arian but in some cases are, who seem to think that John ch. 1 is speaking about the Bible).
* The Orthodox do not deny that she is immaculate; we reject rather the immaculate conception, because this puts the Theotokos in a different ontological condition than the rest of the humanity and in our view this compromises the doctrine of the Incarnation, since we believe that Christ saved us by restoring our fallen human nature by glorifying us through His Incarnation, Baptism, Transfiguration, Passion and Resurrection, most especially on the Holy and Life Giving Cross where on the sixth day, he remade man in His own image, before reposing in a tomb on the seventh, thus just as the womb of the Theotokos once contained Him who is boundless and uncircumscribed, likewise the Holy Sepulchre contained Christ our God on the Seventh Day when He reposed - before His glorious resurrection, the true meaning of the Sabbath - also for this reason the Orthodox venerate the Theotokos and pray for our departed loved ones on Saturday. Indeed for us every Saturday is in some respects like All Souls Day in the Roman Catholic Church, but several saturdays throughout the year are dedicated as Soul Saturdays.
The Saturday preceding All Saints Day, the Sunday following Pentecost, which for us is a feast both of the descent of the Holy Spirit and of the Holy Trinity (this likely being one of several examples where the Western church took a compound feast such as the Epiphany and split it into two feasts, and more recently with the separation of Epiphany Sunday from the feast of the Baptism of our Lord in the 1969 Missal, into three; of course, everyone went along with the separation of the Nativity and Theophany (the feast of the Epiphany, the Baptism of our Lord) except for the Armenians, who alone continue to celebrate them together on the eve and the day of January 6th (thus the Armenians in Jerusalem who, like all Hagiopolitan Orthodox, use the Julian calendar rather than the Gregorian, are the last to celebrate the Nativity, on January 18th and 19th).
