אבן עזרא — ואם תקריב מנחת בכורים לה'

Q — Rashi (citing R' Yishmael in Chazal) says that "אם" in three Torah pesukim means "when" (definite), not "if": "ואם מזבח אבנים תעשה לי," "אם כסף תלוה," and "ואם תקריב מנחת בכורים" — the last identified with the obligatory מנחת העומר. Three exceptions to the otherwise universal rule that "אם" denotes contingency.

A — Ibn Ezra rejects all three exceptions and reads "אם" in its plain meaning. On our pasuk specifically: "מנחת בכורים" is NOT מנחת העומר — that's "ראשית בכורים" (obligatory). "בכורים" (full first-fruits) is a voluntary minchah brought by anyone who wishes. The "אם" denotes its standard contingency. The reading also fits the context — מנחת בכורים sits in a chapter listing voluntary minchot (מנחת מחבת, מנחת מרחשת), each introduced with "אם." Ibn Ezra preserves the universal grammatical rule rather than carving out exceptions. He extends the same to the other two cases: "ואם מזבח אבנים" = "if you merit to enter the Land, then build a stone altar"; "אם כסף תלוה" = "if God gives you wealth enabling lending." A single peshat principle, applied consistently.