only [in the case of] a guarantor appointed by a court of law is no kinyan required; in all other cases, however, kinyan is required. And the law is: [If one] guarantees [a loan] at the time the money is delivered, no kinyan is required; if, after the money is delivered, kinyan is required; [and in the case of] a guarantor appointed by a court of law no kinyan is required, for, having regard to the pleasure he has in the confidence reposed in him, he [wholeheartedly] determines to shoulder the full responsibility.