The short answer of your question is no there's no sahih source for this hadith.
In fact the version of the hadith you quoted is the second narration of abu Dawod, where he just wanted to point at differences in the chain or wording (this happens quite a lot in hadith sources. For example imam Muslim sometimes just mention a narrator chain and say person "X" said like person "Y" referring to an earlier hadith or just quote the addition if any. So one hadith earlier you may read a bit more about abu Damdam:
Is one of you helpless to be like AbuDaygham or Damdam (Ibn Ubayd is doubtful) who would say when morning came: O Allah, I gave my honour as alms to Thy servants? (Sunan abi Dawod)
Abu Dawod one hadith later only mentions the differences in the narrations and narrator chain so he basically compares three narrations we could resume that your quote has two narrations which say the same, but the narrator chain via Hammad ibn Salamah is more trustworthy than that via Hashim ibn al-Qasim. And the earlier narration is maqtu' (incomplete/cut off) and Qatadah is not a Sahabi so it is mawquf too.
So the hadith as is seems complete as the statement is complete even if it might be a bit ambiguous therefore I'll mention a few words from hadith commentaries later.
On other sources of the hadith and its soundness
The hadith or parts of it have wide appearance in hadith compilations the longest I could find is this one:
In the following I'll translate from Arabic as these are my own translations take them carefully!
عَنْ أَنَسٍ رضي الله عنه، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ: ((أَيَعْجِزُ أَحَدُكُمْ أَنْ يَكُونَ كَأَبِي ضَمْضَمٍ؟))، قَالُوا: مَنْ أَبُو ضَمْضَمٍ يَا رَسُولَ اللَّهِ؟ قَالَ: ((كَانَ إِذَا أَصْبَحَ قَالَ: اللَّهُمَّ إِنِّي قَدْ وَهَبْتُ نَفْسِي وَعِرْضِي لَكَ، فَلَا يَشْتُمُ مَنْ شَتَمَهُ، وَلَا يَظْلِمُ مَنْ ظَلَمَهُ، وَلَا يَضْرِبُ مَنْ ضَرَبَهُ)).
On the authority of Anas (ibn Malik) may Allah be pleased with him who said: The Messneegr of Allah Allahs prayers and blessings be upon him asked: "Is one of you helpless to be like Damdam?"
They asked: "who is Abu Damdam?"
He replied : "A man who would say when morning came: O Allah, I gave my self and my honour as alms to you, and he wouldn't curse who curssd him, nor be unjusty to whoever was unjust to him, nor would he hit who hit him"
The hadith as stated above appears according to this article in 'Amal al-Yawm wal-Laylah عمل اليوم والليلة (The deeds of day and night) of ibn As-Sunni ابن السني and in abu a-Sheikh's A-Thawab الثواب (The rewards) and in ibn Hajar's Nataij al-Afkar نتائج الأفكار (The results of thoughts/ideas) and is considered as da'if it partly appears also in the big history (at-Tarikh al-Kabir) of imam al-Bukhari and also in the Musnad of al-Bazzar and many other compilations especially those on weak narrators or weakness of ahadith beside of some biographies like at-Tarikh al-Kabir of al-Bukhari and al-Isabah etc. it was considerd as weak by many scholars among the hafidhs a-Dhahabi and al-'Iraqi and al-Alabni. The mursal version you've quoted is among the strongest.
On the hadith interpretation
Aabadi محمد شمس الحق العظيم آبادي commented in hias 'awn al-Ma'abud عون المعبود -see here in Arabic- on the statement:
O Allah, I gave my honour as alms to Thy servants
As follows:
فلو انتقص أحد منهم من عرضي فليس لي عليه من دعوى الانتصار
If any of them (Allahs servants) took (parts of or) from my honour I wouldn't have any reason to win it back.
So he has no desire of vengeance nor does he want to harm anyone who harms him.
And on the statement:
My honors is for the one who reviles me.
He commented -see here-:
( عرضي لمن شتمني ) : أي متصدق لمن شتمني .
I declare it alms to Allah if anybody reviles me
