Why should not we give salt into bare hands?

Go Bhoo Thila Hiranya Aajya Vaasau Dhaanya Gudaanicha 

Raupyam Lavana Mityaahurdashadaanaah Prakeertitaa

The above sloka states that giving salt is one of the ten named donations. Salt is usually donated at the times of rituals relating to the ancestors or in case of Shani. Giving salt into bare hands symbolises inauspiciousness. So, it is advised not to give salt into bare hands