Guarantee and its meaning.

The Shaykh : A guarantee is when a person comes to the rights holder and says, "You are demanding one thousand riyals from so-and-so," and he says, "Yes," and the guarantor says, "I will wait for him, and I guarantee this one thousand." If he does that, the rights holder has the right to demand the right from both the guarantor and the one for whom the guarantee was made. That is, he can say to the guarantor, "Give me the one thousand," and he can say to the one for whom the guarantee was made, "Give me the one thousand." However, is it a condition for demanding from the guarantor that the one for whom the guarantee was made is unable to pay, or not? Some scholars hold that it is a condition, and that if the rights holder comes to the guarantor and says, "Give me the right you guaranteed on behalf of Zayd," he has no right to do so until he goes to Zayd and says, "Give me my right," and Zayd refuses. However, the well-known view in the school of Imam Ahmad, according to his later followers, is that the rights holder has the right to demand from both: he can demand from the one for whom the guarantee was made and from the guarantor.