Friendship

"Der Grund der Freundschaft heischt die größte Aehnlichkeit der Seelen und Herzen der Menschen."
'The reason for friendship desires the greatest similarity between the souls and hearts of men.' 
Beethoven to Ferdinand Ries (fragment), Baden, 24 July 1804 (BGA 186).  
Possibly a quotation or a proverbial saying. In 1817 Beethoven noted in his diary: 'True friendship can only rest on the union of similar natures', cf. Maynard Solomon, Beethoven's Diary, Bonn 1990, pp. 107 and 172.  
Original not known; text based on the first print in Wegeler/Ries p. 132 ff.  

"Wahre Freundschaft kann nur beruhn auf der Verbindung ähnlicher Naturen"
'True friendship can only be based on the union of similar natures'
In his diary, 1812-1818.  
Probably a quotation from an ancient author. Plutarch, for example, states that ‘among the majority, friendship arises from equality of character and inclination ... and the origin of friendship lies in equality’; see Plutarch's moral treatises in the translation by Kaltwasser, vol. I, pp. 166 and 313. Compare the Greek proverb 'Similarity of manners is the surest bond for lasting friendship'. Beethoven expresses a similar view in a letter to Ferdinand Ries dated 24 July 1804: 'The reason for friendship requires the greatest similarity of souls and hearts'. Beethoven's Diary: 1812-1818, ed. by Maynard Solomon, Bonn: Beethoven-Haus, 2nd edition, 2005, p. 89  

“Einmal kam er im Frühling, brachte uns Veilchen mit den Worten: 'ich bringe Ihnen den Frühling”
‘Once he came in spring and brought us violets with the words: 'I bring you spring' 
Attributed. Fanny Giannattasio del Rio writes in her diary about this alleged statement by Beethoven.  
Giannattasio del Rio, Fanny: Aus Beethovens spätern Lebensjahren: 1. Mittheilungen aus einem Tagebuch, 1857, in: Die Grenzboten, 16 (1857), 1st semester, 2nd volume, p. 27