Thabit bin Ubayd (may Allah have mercy on him) said: I offered the funeral prayer with Sayyiduna Zayd bin Thabit (may Allah be pleased with him) over his mother, and he said four takbirs over her. Imam al-Sha'bi (may Allah have mercy on him) narrates from Sayyiduna Zayd bin Thabit (may Allah be pleased with him) that he said four takbirs over his mother, and he did not grudge her any good.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6951