"Say: Who delivers you from the darkness of the land and the sea," meaning: the afflictions of the land and the sea.
"You call upon Him humbly and in secret," meaning: privately with supplication, "If He delivers us from this" distress, "we shall surely be among the grateful," meaning: the believers.
﴿قُلْ مَنْ يُنَجِّيكُمْ مِنْ ظُلُمَاتِ الْبر وَالْبَحْر﴾ يَعْنِي: كُرُوبَ الْبَرِّ وَالْبَحْرِ.
﴿تَدْعُونَهُ تضرعا وخفية﴾ أَي: سراًّ بالتضرع ﴿لَئِن أنجيتنا من هَذِه﴾ الشدَّة ﴿لنكونن من الشَّاكِرِينَ﴾ يَعْنِي: الْمُؤمنِينَ.