Al-Matalib al-'Aliyah 90 — Running the fingers through the fingers

It is narrated from Sayyiduna Abu Ayyub al-Ansari (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "How excellent are those who do khilal (those who take care of cleanliness)!" The Companions (may Allah be pleased with them) said: O Messenger of Allah, who are these people who do khilal? He (peace and blessings be upon him) said: "Khilal in ablution means that you clean well between your fingers and the roots of your nails; and khilal after food means (removing the particles stuck between the teeth). For there is nothing more painful and burdensome to the angel who is constantly with the servant than that he should detect from any of you the smell of food (arising from the leftover particles)."
The narrator Abu Sawrah in its chain is weak; however, Imam Ahmad bin Hanbal (may Allah have mercy on him) recorded the original narration of this hadith.