Numbers 29:13 - Joseph Benson’s Commentary on the Old and New Testaments

Thirteen young bullocks Thus they continued to be offered seven days successively, with the decrease only of one bullock every day, till on the seventh day only seven bullocks were offered, which in all made seventy bullocks. The rams also were in double proportion to what was usual. This was a vast charge, but more easy at this time of the year than at any other; for this was a time of leisure and plenty; now their barns were full, their wine-presses overflowed, and their hearts were enlarged with joy and gratitude to God for the blessings of the harvest. Yet this troublesome and expensive service made their religion a very grievous yoke, under which the best men among them groaned, longing for the coming of the Messiah, when their own doctors have said, no sacrifices shall remain but those of thanksgiving, praise, and prayer.