Hazrat Yahya bin Saeed (may Allah have mercy on him) narrates that it was conveyed to me that Hazrat Abu Bakr (may Allah be pleased with him) sent armies towards Syria. He (may Allah be pleased with him) set out and was walking behind Yazid bin Abu Sufyan. He (may Allah be pleased with him) said: Surely, I advise you with ten things: Never kill children, neither children nor women nor very old women, and do not cut down fruit-bearing trees. And never destroy inhabited land. And never slaughter goats or cows except for eating. And never cut down a date-palm tree from the top nor burn it, and do not commit treachery, and do not show cowardice.