Musannaf Ibn Abi Shayba 1:1804

Waki’ narrated to us, he said: Sufyan narrated to us, from ‘Abdullah ibn Dinar, from Ibn ‘Umar, who said: "That I had faced from my affair what I have left behind"—meaning regarding the *siwak* (tooth stick)—"is more beloved to me than two servants." He said: And Ibn ‘Umar would not eat food except that he would *yastann*—meaning he would use the *siwak*.