It is narrated from Sayyidah Umm Ayman (may Allah be pleased with her); she said: The Messenger of Allah (peace and blessings be upon him) said: "The thief's hand is not to be cut off except for the theft of something worth a shield." And in the time of the Messenger of Allah (peace and blessings be upon him) its value was set at one dinar or ten dirhams.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21690