This was to commiserate with him following the death of his brother, Emmanuel Adam Mahama.
Mr Obasanjo also said special prayers for Mr Mahama and his family.
Mr Mahama passed on on Friday, December 31, 2021, after a short illness.
He has since been buried at Bole in the Savannah Region in accordance with Islamic customs.
However, the Adua (final funeral rites) have been scheduled for January 30, 2022, at Bole.