O Believers Do Not Forbid the Good Things Allah Has Made Lawful
fiqh
Level: intermediate
special
fqh-056
لَا تُحَرِّمُواْ طَيِّبَٰتِ مَآ أَحَلَّ ٱللَّهُ لَكُمۡ
— المائدة 87
Verse: "O believers, do not forbid the good things Allah has made lawful for you — and do not transgress." (5:87) — Forbidding what Allah made lawful: whoever forbids himself something Allah permitted without legal reason — no obligation but the sin of his belief. "Do not transgress" covers both forbidding the lawful and permitting the forbidden.
Source: Al-Qurtubi (6/279); Ibn Kathir (3/140)
Question: What is the ruling on one who forbids himself something Allah made lawful?
Answer: Prohibited — and the prohibition doesn't legally bind for permissible things. If he intended an oath it requires expiation if he does it.