John Gills Exposition of the Bible Commentary - Leviticus 27:26
Only the firstlings of the beasts ,.... These are excepted from being sanctified, or set apart for sacred uses, for a very good reason, suggested in the next clause: which should be the Lord's firstling, no man shall sanctify it ; it being what he has a claim upon, and ordered to be sanctified to him by a law previous to this, Exodus 13:2 ; wherefore to sanctify such a creature, would be to sanctify what was his before; not merely in a general sense, in which all creatures are his, but... read more
Matthew Henry's Complete Commentary - Leviticus 27:26-34
Here is, I. A caution given that no man should make such a jest of sanctifying things to the Lord as to sanctify any firstling to him, for that was his already by the law, Lev. 27:26. Though the matter of a general vow be that which we were before obliged to, as of our sacramental covenant, yet a singular vow should be of that which we were not, in such circumstances and proportions, antecedently bound to. The law concerning the firstlings of unclean beasts (Lev. 27:27) is the same with that... read more