“Ibn Taymiyah” writes:

“محمد بن علی الجواد کان من اعیان بنی هاشم، و هو معروف بالسخاء و السؤدد و لهذا سمّی الجواد”…

Imam “Jawad” [a.s] was one of “Bani Hashim” well-known figures. He had reputation for lordship and generosity, that’s why he was named “Jawad”.

Minhaj al-Sunna – p 68