وَتَحْمِلُ أَثْقَالَكُمْ ...

And they carry your loads,

meaning the heavy burdens that you cannot move or carry by yourselves,

... إِلَى بَلَدٍ لَّمْ تَكُونُواْ بَالِغِيهِ إِلاَّ بِشِقِّ الأَنفُسِ ...

to a land that you could not reach except with great trouble to yourselves,

meaning journeys for Hajj, Umrah, military campaigns, and journeys for the purpose of trading, and so on.

They use these animals for all kinds of purposes, for riding and for carrying loads, as Allah says:

وَإِنَّ لَكُمْ فِى الاٌّنْعَـمِ لَعِبْرَةً نُّسْقِيكُمْ مِّمَّا فِى بُطُونِهَا وَلَكُمْ فيِهَا مَنَـفِعُ كَثِيرَةٌ وَمِنْهَا تَأْكُلُونَ

وَعَلَيْهَا وَعَلَى الْفُلْكِ تُحْمَلُونَ

And verily, there is indeed a lesson for you in the An'am (cattle). We give you to drink (milk) of that which is in their bellies. And there are numerous (other) benefits in them for you. Of them you eat, and on them and on ships you are carried. (23:21-22)

اللَّهُ الَّذِى جَعَلَ لَكُمُ الاٌّنْعَـمَ لِتَرْكَـبُواْ مِنْهَا وَمِنْهَا تَأْكُلُونَ

وَلَكُمْ فِيهَا مَنَـفِعُ وَلِتَـبْلُغُواْ عَلَيْهَا حَاجَةً فِى صُدُورِكُمْ وَعَلَيْهَا وَعَلَى الْفُلْكِ تُحْمَلُونَ

وَيُرِيكُمْ ءَايَـتِهِ فَأَىَّ ءَايَـتِ اللَّهِ تُنكِرُونَ

Allah, it is He Who has made cattle for you, so that some you may ride, and some you may eat. And you find (many other) benefits in them; you may reach by their means a desire that is in your breasts (i.e. carry your goods, loads), and on them and on ships you are carried. And He shows you His Ayat.

Which, then of the Ayat of Allah do you deny! (40:79-81)

Thus here Allah says, after enumerating these blessings,

... إِنَّ رَبَّكُمْ لَرَؤُوفٌ رَّحِيمٌ ﴿٧﴾

Truly, your Lord is full of kindness, Most Merciful.

meaning, your Lord is the One Who has subjugated the An`am (cattle) to you.

This is like the Ayat:

أَوَلَمْ يَرَوْاْ أَنَّا خَلَقْنَا لَهُم مِمَّا عَمِلَتْ أَيْدِينَآ أَنْعـماً فَهُمْ لَهَا مَـلِكُونَ

وَذَلَّلْنَـهَا لَهُمْ فَمِنْهَا رَكُوبُهُمْ وَمِنْهَا يَأْكُلُونَ

Do they not see, that of what Our Hands have created, We created the An'am (cattle) for them, so that they may own them, and We subdued them so that they may ride some and they may eat some. (36:71-72)

وَالَّذِى خَلَقَ الأَزْوَجَ كُلَّهَا وَجَعَلَ لَكُمْ مِّنَ الْفُلْكِ وَالاٌّنْعَـمِ مَا تَرْكَبُونَ

لِتَسْتَوُواْ عَلَى ظُهُورِهِ ثُمَّ تَذْكُرُواْ نِعْمَةَ رَبِّكُمْ إِذَا اسْتَوَيْتُمْ عَلَيْهِ وَتَقُولُواْ سُبْحَـنَ الَّذِى سَخَّرَ لَنَا هَـذَا وَمَا كُنَّا لَهُ مُقْرِنِينَ

وَإِنَّآ إِلَى رَبِّنَا لَمُنقَلِبُونَ

And He made mounts for you out of ships and cattle. In order that you may ride on their backs, and may then remember the favor of your Lord when you mount upon them, and say:

"Glory be to the One Who subjected this to us, and we could never have it (by our efforts). And verily, to Our Lord we indeed are to return!'' (43:12-14)

Ibn Abbas said,

لَكُمْ فِيهَا دِفْءٌ (In them there is warmth),

refers to clothing;

وَمَنَافِعُ (and numerous benefits),

refers to the ways in which they derive the benefits of food and drink from them.''