 स बद्धस्तेन वल्केन विमुक्तोऽस्त्रेण वीर्यवान्।अस्त्रबन्धः स चान्यं हि न बन्धमनुवर्तते।। 
 On being bound by bark ropes Hanuman was set free from the bond of Brahmastra, since  the bondage of Brahmastra does not tolerate another ordinary bondage.   