Benjamin SLIGHT was born on 1 August 1800 at Nenthorn, Berwickshire, Scotland, and baptized in Nenthorn Kirk on 31 October 1803 with his elder brother John and younger sister Elizabeth. He was the second son of James SLIGHT (1772-1852), gardener to Sir Alexander Don on his Newton Don estate. The SLIGHTs had been gardeners there, off and on, for at least 60 years and had resided during that time in the parishes of Nenthorn, Makerstoun, Ednam and Stichill which lie adjacent to one other. His mother was Hannah DOWNS (c. 1773-1842) and all that is definitely known of her birthplace is that she was born somewhere in England though the exact place could have been as far away as Devon (family tradition) or even as close as Northumberland, only 10 miles away.

Some time before 12 May 1804, when Benjamin's infant twin brothers were buried, the family had moved to the neighbouring parish of Kelso where they remained until at least 15 October 1815 when Benjamin's youngest sister, Christina was baptized there. Benjamin's grandfather, James SLIGHT (1739-?), had worked as gardener at Stodrigs (now part of the Floors Castle estate belonging to the Duke of Roxburghe) in the parish of Makerstoun before 7 June 1772. He had subsequently moved his employment to Blackwater Hall, Ednam, Roxburghshire, not far away on the opposite, eastern side of Kelso, around 1775. Around 1785-6, he worked at Ednam House, the residence of Mrs. Dickson, on the western side of Kelso not too far from the town itself and finally settled down to become a farmer some time before 1797 and owning two horses in that year. Towards the end of the following decade, he was described as an "egg dealer" and was living within the parish of Kelso.

We do not know what kind of education, if any, his grandson Benjamin enjoyed in Kelso during his boyhood; nor the reason why Benjamin and his family left Scotland; nor their whereabouts during the period 1815-1826 (apart from a reference to Benjamin's sister Elizabeth who is said to have married her husband George ROBSON in Jedburgh on 12 August 1819). At the end of this period of mystery, he was, in a published discourse, to "plead the cause of the English Sabbath School System … [which] … has become endeared to my heart by a long acquaintanceship"; such remarks, if taken literally, suggesting that he had been in England, at least, if not in Newcastle on Tyne for quite a number of years. It is not known whether he was in contact with his aunt, Ann SLIGHT (née BEAL), a native of Warkworth, Northumberland, who was living in Alnwick, Northumberland, on 1 January 1811, with her infant son, James Beal SLIGHT, and who was the widow of his father's younger brother, Archibald (1780-1810),.