The MESSENGER OF AllAH (PBUH) Rose up on the Pulpit and Said: "ABU BAKR (R.A) is More kind to ME than all people, both in wealth and in companionship, and whoever I make someone a Khalil (except AllAH), I make ABU BAKR (R.A) A Khalil." Now there is no khalat, but there is brotherhood (fraternity) of Islam, no one's window should remain in the mosque (all should be closed), but the window of ABU BAKR'S HOUSE should be Established.
(Sahih Muslim - 6170)