In the Qur'an, Allah instructs Muhammad to ask forgiveness for his sin

>So know, [O Muhammad], that there is no deity except Allah and **ask forgiveness for your sin** and for the believing men and believing women. And Allah knows of your movement and your resting place.. Surat Muhammad 47:19

My question is, does the Qur'an or hadith specify which sin(s) Muhammad committed? (If he committed sin(s)?)