'Why they did not kill me, why they didn't tie my hands, I don't know,' he said.
Describing his 18-month ordeal, Father Tom Uzhannalil told reporters in Rome he still did not know why he was not killed.
Using the only Arabic he knew, the priest said he told his captors: 'Ana hindiin' ("I am Indian").'
He said: 'Perhaps they wanted some ransom or whatever it is. I only believe that maybe God had put that into their heads when I said, "I am Indian" and they made me sit there while they killed the others, the Sisters.'
Father Tom was from the Salesian religious order and was kidnapped on March 4, 2016 from a home for the old and disabled run by the Missionaries of Charity in Aden, Yemen.
Following his capture, unsubstantiated reports were widely circulated suggesting he was about to be crucified.
The allegations, which appeared to originate in a Facebook post by the Franciscan Sisters of of Siessen in South Africa (since deleted) were shared round the world and widely reported as fact, in spite of repeated denials from senior Catholics and leaders in a position to know whether any information whatsoever had been received about the missing priest.
Despite sparing Father Tom, four nuns and 12 others were murdered in the attack by uniformed gunmen.
'I thank God Almighty for this day, for keeping me safe, healthy, clear minded; my emotions were in control until now,' he said after regaining his composure.
'I don't want to speak too much about the Sisters because I get too emotional,' he said.
Speaking to reporters at the Salesian headquarters in Rome where he is recovering, Father Tom described how he celebrated the Eucharist every day of his captivity and spent his time praying for the Pope, his bishop and 'certainly those Sisters, all those persons whom God had called' on the day he was kidnapped.
He also said he found comfort in the hymn, 'One day at a time, sweet Jesus.'
He would sing in his cell: 'Just give me the strength to do every day what I have to do. Yesterday's gone, sweet Jesus, and tomorrow may never be mine. Lord, help me today, show me the way, one day at a time.'
Although he knows little about the details that led to his release, Father Tom thanked those who helped secure it, including Sultan Qaboos bin Said al Said of Oman, authorities in India, and the Vatican, including Pope Francis.
Father Tom met the pontiff the day after his release, falling on the ground to kiss his feet.