It is reported from the Prophet ﷺ regarding this. It is narrated from Ibn Mubarak that he said concerning this hadith, "It is permissible in the speech of the Arabs, when someone fasts most of the month, to say that he fasted the entire month. It is also said that so-and-so prayed throughout the entire night, even though he may have eaten supper and occupied himself with some of his affairs."It seems Ibn Mubarak considered both hadiths to be in agreement, saying that the meaning of this hadith is simply that he used to fast most of the month.
حدثنا هناد حدثنا عبدة عن محمد بن عمرو حدثنا أبو سلمة
عن النبي ﷺ بذلك وروي عن ابن المبارك أنه قال في هذا الحديث قال هو جائز في كلام العرب إذا صام أكثر الشهر أن يقال صام الشهر كله ويقال قام فلان ليله أجمع ولعله تعشى واشتغل ببعض أمره كأن ابن المبارك قد رأى كلا الحديثين متفقين يقول إنما معنى هذا الحديث أنه كان يصوم أكثر الشهر
No references are available.
[Its isnad is hasan] Bukhari related it in "Fasting," chapter on fasting in Shaban, Hadith: 1969, and Muslim, Hadith: 1156/175, from the hadith of Abu Salama, similarly.