In Tafsir Ibn Kathir, you can find many other details or stories that aren't mentioned in the beautiful Qur'an, and not even by the Holy Prophet (may peace and blessings of Allah be upon him). For example, in Surah Al-Baqarah 2:246,
Have you not considered the assembly of the Children of Israel after [the time of] Moses when they said to a prophet of theirs, "Send to us a king, and we will fight in the way of Allah "? He said, "Would you perhaps refrain from fighting if fighting was prescribed for you?" They said, "And why should we not fight in the cause of Allah when we have been driven out from our homes and from our children?" But when fighting was prescribed for them, they turned away, except for a few of them. And Allah is Knowing of the wrongdoers.
Ibn Kathir records that Wahab bin Munabbih (وهب بن منبه) (may Allah have mercy on him) said lots of details about this Ayah, such as the full name of the Prophet (may peace be upon him), here:
شمويل بن بالي بن علقمة بن يرخام بن إليهو بن تهو بن صوف بن علقمة بن ماحث بن عموصا بن عزريا بن صفنيه بن علقمة بن أبي ياسف بن قارون بن يصهر بن قاهث بن لاوي بن يعقوب بن إسحاق بن إبراهيم الخليل عليه السلام .
And he also described the state the Children of Israel were at the time, and how the mother of the Prophet (may peace be upon him) gave birth to him. But he (may Allah have mercy on him) was only a Tabi'i, how did he know all this information that wasn't in the Sunnah or the Qur'an? There also many other things some of the Sahaba (may Allah be pleased with them) and some of the Tabi'in (may Allah have mercy on them) said, but how do they know all that?
Jazakum Allah khayran