According to the lexical defintion...

According to the lexical defintion, the word 'شمر' refers to 'getting ready', and it is possible that originally, it was used by the ‘Arabs when they used to say: شَمَّرَ عَنْ سَاقَيْهِ. “He rolled his garments upto his shin (in preparation of some work).” Traditionally, ‘Arab men wear long, flowing robes, however when working, this clothing would not be suitable.

Thus, when they wished to do any form of physical labour, they would pull up their clothing and hold it up with their hands, or would pull the clothing up and tie a long piece of cloth around the waist as a belt. In this way, the long gown would reach halfway up their legs or up to the knees and thus: شَمَّرَ عَنْ سَاقَيْهِ. is actually a figure of speech meaning that one should get ready to work and do some laborious task.

The Prophet (S) then said, “…prepare yourselves since this is a very serious issue which concerns the fire of hell and the accountability and reckoning (of your deeds)…” The Second Point: Prepare the things which you shall need (for this journey) The word 'أهبة' refers to the provisions (and is similiar to the meaning of the word in the first commandment mentioned above). What is the difference between the words 'شمروا' and 'تأهبوا' as both are closely related to 'getting ready'?

The difference between these two words as that where as 'شمروا' means that the person himself gets ready, the word 'تأهبوا' means that one prepares the necessary items which are needed. We know that for any journey one takes - of which the journey of the Next Life is one of them - one must be prepared.

In addition, one must also prepare the necessary items which are needed on the trip… The Third Point: Provisions for the journey must be gathered Other than the items needed (for this long journey of the Next Life) such as the stead and baggage, one also needs other things as without doubt, the departure time is close and the trip is a long.

These two statements of the tradition under discussion are not contradictory to one another since the meaning of the departure time refers to when the journey shall start, and the journey shall start very soon. However at same time the journey is also a long one!