Whenever Messenger of Allah ﷺ intended to carry out a Ghazwa, he would use an equivocation to conceal his real destination till it was the Ghazwa of Tabuk which Messenger of Allah ﷺ carried out in very hot weather. As he was going to face a very long journey through a wasteland and was to meet and attack a large number of enemies. So, he made the situation clear to the Muslims so that they might prepare themselves accordingly and get ready to conquer their enemy. The Prophet ﷺ informed them of the destination he was heading for. (Using translation from Bukhārī 2948)
سَمِعْتُ كَعْبَ بْنَ مَالِكٍ ؓ يَقُولُ كَانَ النَّبِيُّ ﷺ قَلَّمَا يُرِيدُ غَزْوَةً يَغْزُوهَا إِلَّا وَرَّى بِغَيْرِهَا حَتَّى كَانَتْ غَزْوَةُ تَبُوكَ فَغَزَاهَا رَسُولُ اللهِ ﷺ فِي حَرٍّ شَدِيدٍ وَاسْتَقْبَلَ سَفَرًا بَعِيدًا وَمَفَازًا وَاسْتَقْبَلَ عَدُوًّا كَثِيرًا فَجَلَّى لِلْمُسْلِمِينَ أَمْرَهُمْ لِيَتَأَهَّبُوا أُهْبَةَ عَدُوِّهِمْ وَأَخْبَرَهُمْ بِوَجْهِهِ الَّذِي يُرِيدُ