What was ancient Israel’s population? The statistic in Numbers 1:46 implies a nation of millions exiting from Egypt. Was it really that high?
Israel’s population was in the millions, but the question is whether the army was really as large as 603,550 at the time of the Exodus. To most scholars this figure seems high, perhaps a retrojection from later times. Note that all tribal totals end in 00 except Gad’s, which ends in 50. This may indicate more than mere rounding.
Numbers 10:36 mentions “countless thousands.” The Hebrew word for thousand (’elef ) also means “clan.” Perhaps the impressive numbers in the account of the growth of the Hebrews originate from this meaning of ’elef. This would explain why the entire army was deployed against Ai, a city of barely 5000 men (12,000 total population, Joshua 8:25), or why the Israelite army numbers only 40,000 in the battle of Jericho (Joshua 4:13). The original exodus population would still have been sizeable, though national population did not reach the millions until the time of the monarchy.
We might also take into account Exodus 15:27, where it seems that 70 palm trees provide fruit and shade for the fledgling nation, and 12 springs provide sufficient water. While it is easy to imagine a group in the hundreds or thousands subsisting on the water of 12 springs, it is quite difficult (for me, at least) to believe millions of people were sustained by so little water — unless we posit a miracle. (In which case we ought to ask which is more likely: that there was an unrecorded miracle, or that our interpretation may have made some incorrect assumptions.)