'Ûlay (אֻלַי, Strong's #194), “peradventure; perhaps; suppose; if; less.” The 43 occurrences of this word appear in every period of biblical Hebrew.
This word meaning “peradventure or perhaps” usually expresses a hope: “Behold now, the Lord hath restrained me from bearing: I pray thee, go in unto my maid; it may be that I may obtain children by her” (Gen. 16:2—the first occurrence). Elsewhere 'ûlay expresses fear or doubt: “Peradventure the woman will not be willing to follow me unto this land; must I needs bring thy son again unto the land from whence thou camest?” (Gen. 24:5).
If followed by another clause the word almost functions to introduce a protasis: “Peradventure there be fifty righteous within the city: wilt thou also destroy …” (Gen. 18:24).
In Num. 22:33 the word has a different force: “And the ass saw me, and turned from me these three times: unless she had turned from me, surely now also I had slain thee, and saved her alive.”