Musnad Ahmad 941:88

Yahya narrated to us, from Abd al-Malik, Ata’ narrated to us, from Usama ibn Zayd: That he and the Messenger of Allah, peace and blessings of Allah be upon him, entered the House (the Kaaba). He ordered Bilal, and he closed the door. The House at that time was upon six pillars. He proceeded until he came to the two pillars that are adjacent to the door, the door of the Kaaba, and he sat. He praised Allah and extolled Him, and he asked Him and sought His forgiveness. Then he stood until he came to what faced the back of the Kaaba, and he placed his face and his body against the Kaaba, and he praised Allah and extolled Him, and he asked Him and sought His forgiveness. Then he turned until he came to every corner of the corners of the House, and he faced it with the declaration of Allah’s greatness (Takbir), the declaration of His oneness (Tahlil), the declaration of His perfection (Tasbih), the praise of Allah, the seeking of His forgiveness, and the asking of Him. Then he went out and prayed two rak'ahs outside the House, facing the direction of the Kaaba, and then he departed. He said: "This is the Qibla, this is the Qibla."