Al-Dhahabi

Shams ad-Dīn adh-Dhahabī (شمس الدين الذهبي), also known as Shams ad-Dīn Abū ʿAbdillāh Muḥammad ibn Aḥmad ibn ʿUthmān ibn Qāymāẓ ibn ʿAbdillāh at-Turkumānī al-Fāriqī ad-Dimashqī (5 October 1274 – 3 February 1348) was an Athari theologian, Islamic historian and Hadith scholar.

195922

It is untrue. Imam Ali (AS) never gave any of his sons the  name of Umar Ibn Khattab.

We have narrations that one of his sons was called Amr عمرو not Umar عمر . Amr عمرو  is a different name.

Wassalam.