It is narrated from Hazrat Zaid bin Arqam (may Allah be pleased with him) that among the children, Hazrat Ali (may Allah be pleased with him) was the first to accept Islam along with the Noble Prophet (peace and blessings be upon him).
Hadith Referenceمسند احمد / تتمہ مُسْنَدِ الْكُوفِيِّينَ / 19306
Hadith Gradingحکم دارالسلام:إسناده ضيعف لجهالة أبى حمزة. وقوله الحافظ ابن حجر : "وثقة النسائي" وهم