Shmuel said the following three
rulings: partners can establish chazakah against each other, they can
testify on behalf of the other, and they can become paid custodians one
of the other.
How can Shmuel contradict the accepted rule that partners cannot establish chazakah? – His version of this ruling was that they can. Shmuel
explains: it is normal for partners to expect regular returns from
their field. If one of them occupied it for three consecutive years, he
is believed to say that he bought his partner out, for otherwise they
would alternate more frequently.
How can he testify for his partner, if he has an interest in the outcome? He needs to renounce his share.