It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Noble 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 the utensil of any one of you, he should wash it seven times. No one should be prevented from using extra water so that by it the extra grass may be withheld. And it is the right of the camel that when it is brought to the watering place, it should be milked there.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 10252