Epistularum libri
Ex libro IX
Pomponius, Epistles, Book IX. A slave who is to be liberated on condition of paying a certain sum of money to Titius will become free if he pays the money out of his peculium, even without the consent of the heirs; but if Titius knowingly accepts the money against the consent of the heirs, he will only be considered to hold it as the possessor, and not the owner, and the heirs, who were unwilling that it should have been paid, can deprive him of it.
Pomponius, Epistles, Book IX. If you promise to deliver me a slave belonging to another, or if you have been ordered to do so by will, and the slave should be manumitted by his master before you are obliged to deliver him to me, this manumission will have the same effect as death, for if the slave should die you will not be liable. 1If, however, anyone who has promised to give a slave, and, having been appointed an heir by the master, he delivers him to be free under a condition, he will be released.