Sayyiduna Jabir said: The Prophet (peace and blessings be upon him) used to prostrate on his forehead together with the hairline.
Imam Abu Ya'la and Imam al-Tabarani in al-Mu'jam al-Awsat recorded it, except that he (al-Tabarani) recorded these words: "on his forehead at the hairline." Its chain contains Abu Bakr bin Abdullah bin Abi Maryam, who is da'if (weak) because of his confusion (ikhtilat).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 2755