The reason for the naming of the chapters of the Qur'an as they are now

Question:
Did the names of the chapters of the Noble Qur'an come through the revelation sent down to the Prophet (peace and blessings be upon him), or were they named afterwards? And why was the chapter al-Baqarah given this name?

Answer:
It appears—and Allah knows best—that they were named through the independent legal reasoning (ijtihad) of the Companions (may Allah be pleased with them). As for al-Baqarah, al-Imran, and al-Nisa, it appears that they were named through the independent legal reasoning of the Companions (may Allah be pleased with them and grant them satisfaction). It is established from the Prophet (peace and blessings be upon him) that he recited al-Baqarah, al-Nisa, and al-Imran in one unit of prayer during the late-night voluntary prayer, in the narration of Hudhayfah and other narrations. So perhaps they heard this naming from the Prophet (peace and blessings be upon him), and some of it was through their own independent legal reasoning, may Allah be pleased with them.
And al-Baqarah was named so because it contains a mention of the cow; al-Imran because it contains a mention of the family of Imran; al-Nisa because it contains a mention of women [al-Nisa:3]; al-Ma'idah because it contains a mention of the table; al-An'am because Allah mentioned the cattle in it; al-A'raf because it contains a mention of the elevated places; al-Anfal because it contains a mention of the war spoils; al-Tawbah because it contains a mention of repentance; Yunus because it contains a mention of Yunus; Hud likewise; Yusuf likewise; al-Ra'd likewise; Ibrahim likewise; al-Hijr likewise; al-Nahl likewise... and so on. Yes.