André Lacocque, in his commentary on the book of Daniel, wrote that
The title given to God is עתיק יומין, a
unique expression, although corresponding titles can be found in 1 Enoch
46:1-2; 47.3; and 98.2: ‘Head of Days’ (see also 55.1; 60.2; 71.10-13. IN these
texts the title is perhaps a later interpolation). The parallels within
canonical Scripture are more ideological than linguistic (see Isa. 44.6; Ps.
55:19). Charles cites Wisd. (Syriac text) 2.10: ‘old man rich in days’, which
he compares to Gen. 24.1. But in both cases it is a question of men and not of
God. 1 Baruch 4.10, 14, and 20 call God ‘the Eternal’. The origin of this notion
should probably be sought in the literature from Ugarit where the high god El
is mlk ab shnm (king, father of years) (see 1 AB 1.7). (André Lacocque, The
Book of Daniel [trans. David Pellauer; Atlanta: John Knox Press, 1979], 142)
Gen 24:1, referenced above, reads as follows:
Now Abraham was old, and well
stricken in age (זקן בא בימים), and
the Lord had blessed Abraham in all things.