Here is a Russian icon with a large crowd of figures:
The inscription at the top tells us who they are;
ОБРАЗЪ СОБОРЪ СВЯТЫХ
All together it reads:
ОБРАЗЪ СОБОРЪ СВЯТЫХ СЕМИДИСЕТИ АПОСТОЛОВ
OBRAZ SOBOR SVYATUIKH SEMIDISETI APOSTOLOV
“IMAGE of the ASSEMBLY of the HOLY SEVENTY APOSTLES”
You may recall that a Sobor — an Assembly — is also the name used for a commemoration of a group of saints or angels, and in fact there is an “Assembly of the Holy Seventy Apostles” commemorated annually in the Eastern Orthodox Church calendar.
The problem is that their names — and even their numbers — vary from account to account.
If one reads older Bible translations, one finds the Seventy mentioned in Luke 10:1 (and 10:17), for example in the King James version:
“After these things the Lord appointed other seventy also, and sent them two and two before his face into every city and place, whither he himself would come.”
That is essentially what we find in Church Slavic Bibles as well, for example in the “Elizabeth” Bible:
По сих же яви Господь и инех седмьдесят, и посла их по двема пред лицем Своим во всяк град и место, аможе хотяше Сам ити:
And we find it in the traditional Byzantine Greek text:
However, if we look at more recent translations, we find something different — for example in the English Standard Version:
“After this the Lord appointed seventy-two others and sent them on ahead of him, two by two, into every town and place where he himself was about to go.
And if we look at more recent editions of the Koine Greek text of Luke 10:1, we also find that has changed to “seventy-two,” for example in Tyndale House SBL:
Μετὰ δὲ ταῦτα ἀνέδειξεν ὁ κύριος καὶ ἑτέρους ἑβδομήκοντα δύο καὶ ἀπέστειλεν αὐτοὺς ἀνὰ δύο δύο πρὸ προσώπου αὐτοῦ εἰς πᾶσαν πόλιν καὶ τόπον οὗ ἤμελλεν αὐτὸς ἔρχεσθαι.
So in the newer texts and translations of Luke, seventy has become seventy-two.
This is not, however, a new problem, and it originates in the variant readings found in old Greek manuscripts of Luke. Some say there were seventy apostles sent out in Luke 10, while others say seventy-two. Modern critical Greek texts of the New Testament tend to prefer the “seventy-two” reading, because it is found in Papyrus 75 ( Papyrus Bodmer XIV–XV ), as well as attested in Papyrus 45 (Chester Beatty Papyrus) for Luke 10:17; and it is the reading also found in Codex Vaticanus and several other manuscripts, while the reading “seventy” is found in some such as Codex Alexandrinus. Modern manuscript scholars presume that “seventy-two” was likely the earlier reading, and that “seventy” came from revising the number to fit the frequent use of the number seventy for various purposes elsewhere in the Bible, while seventy-two is an uncommon number found mentioned only once in quite another biblical context.
In any case, though in its calendar and liturgy the Eastern Orthodox churches prefer to use the number “Seventy” for the apostles sent out in Luke 10, writers such as Dimitriy Rostovskiy were familiar with the discrepancy. In his discussion of the “Assembly of the Holy Seventy Apostles” commemoration, he noted that some of the Seventy had fallen “from the faith and dignity of their office,” one even becoming a pagan priest; and he mentions two names that were added to the list — Dionysius the Areopagite, and Simeon Niger. The old lists naming the Seventy or Seventy-two do not always agree on all the names. You will find Dimitriy Rostovskiy’s discussion of the matter here:
If we look more closely at the icon shown above, we can see that the “Seventy” are all clustered around a symbolic central church building that is “founded on a rock”:
(Courtesy of Antonio Caldeo)