Among the people who are nishba ve-notel – who can take an oath affirming the veracity of their claim and collect – are plaintiffs whose adversaries in court are people who are suspect and cannot take an oath themselves. Thus, in cases where the defendant would ordinarily have been obligated to take an oath and free himself from payment, if the defendant is a gambler like a dice player, or mafriḥei yonim – “people who make birds fly” – he cannot. Similarly, if he is someone who markets produce from the Sabbatical year, the plaintiff will take an oath in court and collect.
The Gemara in Massekhet Sanhedrin (25a) offers two explanations for mafriḥei yonim – “people who make birds fly.” One approach is to explain that it is pigeon racing; the other approach suggests that it is ara – that is, training a pigeon to entice other birds to follow it. The Ran explains that these two reasons are dependent on how we define the underlying problem with gambling. The Mishna taught that a mesaḥek be-kuvya – a dice player – is disqualified from testifying in court. Rami bar Ḥama taught that the problem with a dice player is one of asmakhta – when gambling, neither side thinks that he will lose which will lead to a situation where the winner takes the loser’s money against his will. It is possible that in different types of betting players recognize different levels of possibility that they might lose. The Mishna therefore needs to mention different types of gambling separately. Rav Sheshet, on the other hand, taught that the problem with a dice player is that he is eino osek be-yishuvo shel olam – that someone who makes his living by gambling is not involved in positive community activities. This explanation applies equally to dice playing and pigeon racing, so according to this approach we must have an alternative explanation for the case of mafriḥei yonim.
The practice of ara – where a hunter trains his animals to entice others to return with it – would be permissible in settings where the animal brings wild animals back to its owner. The problem comes when the trained bird entices domesticated birds to return with it. Those domesticated birds that grow up in dovecotes are considered to be the property of the person who raises them – at least on a rabbinic level. Thus, someone who lives in a city or another populated area and trains his birds to bring home other birds, is assumed to be a thief and cannot be trusted to testify in court.