Sayyiduna Ismah (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "When one of you has prayed Jumu'ah, he should not pray anything after it until he has spoken or gone out (of the mosque)."
Al-Tabarani recorded it in al-Mu'jam al-Kabir; its chain contains al-Fadl bin al-Mukhtar, who is extremely da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 3189