It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Holy Prophet (peace and blessings be upon him) said: When any one of you performs istinja with stones, he should use an odd number of stones. When a dog licks any of your vessels, he should wash it seven times. And no one should be prevented from using excess water so that extra grass can be withheld through it. And it is the right of the camel that when it is brought to the watering place, it should be milked then.